The after-COS expenses related to normal operation of the business including R&D, advertising, salaries, rent and utilities, but excluding interest expense, taxes, and exceptional (one-time) charges.
Overheads may also be attributable to specific areas or operations of the business, e.g. Factory Overheads.
Generally Overheads can also be called Operating Expense or OpEx. See discussion at Costs & Expenses.
The terms Overhead, Operating Expense, Indirect Costs, and Fixed Costs are very similar. Check how each term is used in your company.
term list.